Top 45 network primetime telecasts of all time (1964-Present)(from January 1964 to February 2008; ranked by rating, or "Percentage of Households." Households could include many viewers; share is the percentage of television sets in use tuned to a specific program; source: Nielsen Media Research and Variety)

Few post-1990 telecasts are listed. With the ubiquity of cable and satellite television, typical American households have a far greater choice of programming: dozens of specialty and broadcast channels, as opposed to the handful of broadcast channels during the era represented by most programs on this list. More recently, the Internet has also drawn viewers away from television. Future programs with viewership levels (in terms of percentage of TV households) that rank high on this list are probably unlikely to exist in the foreseeable future except for a Super Bowl.